Generally, the commercially available articulated bus uses a hydraulic damping system to stabilize the body of the articulated bus while the articulated bus is turned or driven at a high velocity. However, in case that sudden shock or tire slip occurs, the hydraulic damping system cannot make an immediate response. Consequently, it is difficult for the current wheel traction system to control the angle of the joint. When the articulated bus is driven at a high velocity, a trailer frame of the articulated bus is unavoidably subjected to shake. If the passenger has many choices, the passenger prefers the ordinary bus because the comfort of the articulated bus is unsatisfied.